Hydrogen peroxide solutions have been used for many years for a variety of purposes, including bleaching, disinfecting, and cleaning a variety of surfaces ranging from skin, hair, and mucous membranes to contact lenses to household and industrial surfaces and instruments. Unfortunately, unless stringent conditions are met, hydrogen peroxide solutions begin to decompose into O2 gas and water within an extremely short time. Typical hydrogen peroxide solutions in use for these purposes are in the range of from about 0.5 to about 10% by weight of hydrogen peroxide in water. The rate at which such dilute hydrogen peroxide solutions decompose will, of course, be dependent upon such factors as pH and the presence of trace amounts of various metal impurities, such as copper or chromium, which may act to catalytically decompose the same. Moreover, at moderately elevated temperatures the rate of decomposition of such dilute aqueous hydrogen peroxide solutions is greatly accelerated. Hence, hydrogen peroxide solutions, which have been stabilized against peroxide breakdown, are in very great demand.
Stabilizers, which are usually sequestering agents, are normally added to hydrogen peroxide solutions to combat decomposition due to trace impurities, mainly dissolved metals. Many types of compounds have been used to fill this function, such as diols, quinones, stannate salts, pyrophosphates, various aromatic compounds and amino carboxylic acid salts. However, many of the previously suggested compounds have various issues and challenges associated with them, such as toxicity, environmental impact and poor performance.
Examples of specific compounds that have been suggested for use in solutions to protect against hydrogen peroxide decomposition include sodium phenolsulfate; sodium stannate; N,N-lower alkyl aniline, sulfamic acid, sulfolane, and di-straight chain lower alkyl sulfones and sulfoxides; phosphonic acids and their salts; acrylic acid polymers; polyphosphates; polyamino polyphosphonic acids and/or their salts; and specific combinations (or blends) of such compounds. However, in addition to toxicity and environmental impact concerns, many of these suggested compounds or blends have other drawbacks. For example, use of the specific stabilizer(s) either requires specific conditions to provide adequate hydrogen peroxide stability, such as specific pH levels, e.g., acidic conditions, or relatively low hydrogen peroxide concentrations, or has poor stability performance. The poor stability performance can either be poor stability performance generally or poor stability performance in specific formulations that contain other destabilizing components, e.g., surfactants.
Despite considerable efforts which have been applied with available stabilizer compounds to solve the problem, there still exists a need to provide hydrogen peroxide solutions which are highly stable without one or more of the aforementioned drawbacks and disadvantages.